It applies typically to determining at least one rolling or “running” condition of a motor vehicle tire on the ground. In particular, the rolling conditions determined can be used to determine states or parameters of the bonding at the interface between the tire and the ground, such states or parameters serving in particular for implementation in systems for controlling the dynamics of the vehicle, such as, for example, an Anti-lock Braking System (ABS) or an Electronic Stability Program (ESP).
In order to determine a rolling condition, it has been proposed to analyze how the speed of rotation of the tire changes, in particular by comparing the variations in the respective speeds of rotation of the two wheels on the same axle. However, that determination strategy is not satisfactory, in particular due to its relative nature, but also due to the large number of parameters influencing the relative speeds of the wheels on the same axle (e.g. cornering). Therefore, the reliability and the accuracy of the rolling condition that is determined are, in particular, not compatible with application in a dynamic safety system of the vehicle.
In order to improve that determination strategy, it has been proposed to analyze the speed of rotation of the tire temporally so as to identify a law for determining a rolling condition. Unfortunately, that strategy does not make it possible to solve the above-mentioned problems, in particular due to the fact that the law is heavily dependent on the variations in the speed of rotation.
It is also known, from Document WO-A-00/01545, that a method exists for detecting a flat-tire rolling condition of a tire of a vehicle. In that method, the angular speed of rotation of the wheel is analyzed by spatial Fourier transform so as to use the variations in energy in the vicinities of the harmonics of the rotation. Although that strategy makes it possible to overcome the constraints inherent to temporal analysis, it does not make it possible to obtain satisfactory reliability in determining the flat-tire rolling condition.